HD6432142 datasheet(879/1177 Pages) RENESAS

879 / 1177 page

Section 26 Electrical Characteristics

Rev. 4.00 Sep 27, 2006 page 835 of 1130

REJ09B0327-0400

26.3.7

Usage Note

(1) The F-ZTAT and mask ROM versions have been confirmed as fully meeting the reference

values for electrical characteristics shown in this manual. However, actual performance

figures, operating margins, noise margins, and other properties may vary due to differences in

the manufacturing process, on-chip ROM, layout patterns, etc.

When system evaluation testing is carried out using the F-ZTAT version, the same evaluation

tests should also be conducted for the mask ROM version when changing over to that version.

(2) On-chip power supply step-down circuit

The following products incorporate an internal power supply step-down circuit, which

automatically drops down the internal power supply voltage to the optimum internal voltage

level: the F-ZTAT A-mask versions of the H8S/2148, H8S/2147, and H8S/2144

(HD64F2148A, HD64F2147A, and HD64F2144A) and the mask ROM versions of the

H8S/2148, H8S/2147, H8S/2144, and H8S/2143 (HD6432148S, HD6432148SW,

HD6432147S, HD6432147SW, HD6432144S, and HD6432143S).

The voltage-stabilization capacitor (0.47

µF one or two connected in group) must be connected

between the VCL (internal power supply step-down) and VSS pins.

Figure 26.3 shows the connection of the external capacitors.

For the 5- or 4-V version whose power supply (V

CC) voltage exceeds 3.6 V, do not connect the

VCL pin in a product incorporating an internal step-down circuit to the V

CC power supply.

(Connect the VCC1 pin to the V

CC power supply as usual.)

For the 3-V version whose power supply (V

CC) voltage is 3.6 V or lower, connect both the

VCL and VCC1 pins to the system power supply.

When changing from the F-ZTAT versions not incorporating an internal step-down circuit to

the F-ZTAT A-mask versions or mask ROM versions incorporating an internal step-down

circuit, the VCL pin has the same pin location as the VCC2 pin. Therefore, note that the circuit

patterns differ between these two types of products.

HD6432142 Datasheet(PDF) 879 Page - Renesas Technology Corp